I've found that On the Issues has some odds ways of tabulating their assessments. I don't really trust the site, and haven't used it for months. Regardless of who the politician is, OtI is the last place I'd go to get info about them.
Have you taken the worlds smallest political quiz? It’s at the bottom of the screen and I used to love that site but looking today at John McCain - he’s not right conservative and it says he is.
It did, however, peg me correctly.